Industrialized, as well as developing nations, currently face enormous solid waste disposal problems. Additionally, as technological advances lead to increased individual wealth and a greater distribution of wealth among a larger populace, more and more people are likely to increase their consumption of energy and consumer goods, in effect, increasing their production of solid waste. Methods of addressing solid waste disposal issues typically take the form of the clichéd mantra: Reduce, Reuse, Recycle. As the well known saying indicates, individuals can reduce the solid waste burden by 1.) reducing their use of goods and services, 2.) reusing products more than once before being finally disposed, or 3.) recycling old products into new products. However, while the amount of raw materials required for the manufacture of many consumer products can be reduced and some consumer products, for instance: aluminum cans, plastic bottles, paper and cardboard, are easily reused or recycled, many consumer products are not. One consumer product not easily reused or recycled that represents an enormous solid waste disposal problem is discarded automobile and truck tires.
It is estimated that over 253 million waste tires are generated throughout the United States in one year alone, which represents roughly one tire for every person. According to Waste Age Magazine, scrap tires generate 3.9 million tons or 1.9% of municipal solid waste (MSW) by weight in the United States per year. Approximately 3.2 million tons of tires are incinerated or placed in landfills each year. In New York State alone, the Department of Environmental Conservation has estimated that there are more than 100 waste tire dumpsites that contain over 27 million tires; industry suggests that the number of tires stockpiled in New York is even greater and may range between 50 and 100 million tires.
Because of its physical characteristics, the vulcanized rubber pneumatic tire has proved to be both a blessing and a curse. Tires are manufactured to be durable; they withstand extreme environments and they do not easily wear out. However, because of these same advantageous properties, there is also no real easy way to dispose of them.
Three methods for disposing tires are currently practiced; tires are incinerated, buried or stockpiled. Incineration has been so unsatisfactory that it is now illegal in most jurisdictions. Burning tires causes a horrible stench and pollutes the air with toxic fumes and particles harmful to all life forms. Even expensive modern incineration devices, complete with scrubbers for the exhaust fumes, are inferior at destroying old tires. The steel belting materials clog the incinerator while the particulate carbon and sulfur compounds tend to foul the scrubbers. Burying waste tires is not a good solution either; tires have a tendency to prematurely fill dumpsites because their hollow shapes are particularly volume consuming and they do not easily compress or nest within one another. In addition, buried tires can pose problems if the tire compresses within the landfill and then rises up later and resurfaces. Because of the problems related to their disposal by burying, forty-four states currently restrict tire disposal at landfills. Tires that are not buried represent enormous public health problems as they can be fire hazards or serve as fertile breeding areas for mosquitoes and other vectors that can harbor disease such as West Nile Virus.
The difficulty in discarding worn out tires and the energy and raw materials required to manufacture them has inspired much effort to refurbish them for further use by retreading. These efforts have spawned entire industries presently listed on the New York Stock Exchange. However, there are several major problems with producing re-treads. The new tread which is to be bonded to the old tire must be produced somewhere. Extensive amounts of energy are used to produce the heat required to bond the new tread to the old tire and, even then, that crucial bonding is not always well accomplished. In sum, there is probably as much energy used in pollution produced in the manufacture of a re-treaded tire as in the production of the original tire. Here, as with incineration, the steel belts and cords used in modern tires pose severe obstacles to the successful completion of the process. Not all tires can be effectively recycled by the retreading process. For example, if the sidewall or sealing bead is damaged the tire cannot be reclaimed. In addition, the tire must have sufficient tread and meet stringent standards of flexibility, strength, air permeability, and appearance.
Recycling old tire carcasses into other useful articles has been pursued with limited success. Some propose the shredding of old tires for use as insulation material, perhaps mixed with other insulation materials such as vermiculite. This proposal does indeed recognize the important property of extremely low thermal conductivity of tires. However, the shredding process is difficult as steel belts are imbedded in the old tires.
There have also been numerous proposals to create all kinds of decorative and ornamental articles from the tires. Examples of such uses are flower planters, landscape dividers and mulch material. Two other applications of limited but useful merit will be familiar to all. Anyone from a farm or rural community will have seen a tire hung from a rope to form the familiar “tire swing”. Anyone living on or near a body of water will have seen old tires attached to the sides of docks for cushioning the impacts of boats. These particular uses of waste tires highlight the important and useful impact absorption properties of the tire material.
Numerous United States patents have been granted for various and sundry articles made from old tires. The largest group of these patents are concerned with providing highway safety dividers or barriers thus effectively utilizing the inherent impact energy absorption characteristics of the rubber. Bruner et al, U.S. Pat. No. 4,186,913, shows an arrangement of side by side upright tire casings supported in a solid rubber block which is poured around the lower portions of the tires. Bruner also mentions the possible use of this arrangement as a breakwater. Ward, U.S. Pat. No. 4,030,706, shows a highway bumper guard made from two tire casings arranged concentrically within one another and with the inner casing being filled with particulate material such as sand. Ward recognizes that this arrangement will absorb impact energy by virtue of the friction between the concentric tires. Yoho, U.S. Pat. No. 4,066,244, shows an arrangement of upright tire casing connected together in transverse lines and rows for the purpose of absorbing impact energy. Schaaf et al, U.S. Pat. No. 4,312,600, discloses a traffic barricade or marker whose base is formed from a horizontal tire casing. Schaaf recognizes that the interior portion of the tire casing may be filled with a buoyant material thus forming a buoy marker.
Other miscellaneous exploitations of used tire casings are shown by Doring, U.S. Pat. No. 4,142,821 and by Moore, U.S. Pat. No. 4,022,434. Doring shows ground stabilization devices for embankments, etc. made from variously interconnected loops of tire treads with the sidewalls removed. Moore shows a means of stacking and interconnecting upright tires to form a fence. The tire fence is supported by partially burying the lower course of tires. Moore recognizes yet another important property of the tire material, low electrical conductivity. Moore exploits this property by stringing electrified barbed wire directly from his fence without the need for expensive electrical insulator offset devices of any kind.
The many and varied previous uses for old tire casings serve to illustrate and take advantage of the important property of chemical inertness. Tire casing material will not rot, decay, decompose, deteriorate, or easily disintegrate. Tire casings are impervious to attack from mold, fungus, or bacteria, or other microorganisms. Insects, rodents, birds, bats, deer, barnacles, and other animals cannot destroy tire casings. Corrosive agents, such as salt water and most acids, do not harm tire casings. Prolonged exposure to ultra-violet radiation does not degrade tire casing material. Tire material will withstand extreme climatic temperature ranges without substantial deterioration of its excellent strength and toughness characteristics. Thus, discarded tires recycled in the form of construction materials would be particularly advantageous.
It is estimated that there are between 80 and 135 million wood utility poles in the U.S., and that four million wood poles need to be replaced annually because of routine maintenance, accidents, construction, and the woodpecker. According to the Wall Street Journal, “in a typical mid-size city, roughly 1,000 telephone poles have to be replaced every year because birds—and then rain cause them to rot.”
Wood preserved utility poles represent enormous sources of toxic chemicals that are released into the environment and wood utility poles contain some of the most deadly, ubiquitous and persistent chemicals known to man. The major wood preservatives, including pentachlorophenol (penta or PCP), creosote, and arsenicals (Copper Chromium Arsenate (CCA)), are ranked among the most potent cancer agents, promoters of birth defects and reproductive problems, and nervous system toxicants. In sum, wood utility poles contain chemicals that, if used in other contexts, would be labeled hazardous waste as a result of their containing dioxin, furans and hexachlorobenzene. According to a report published by the National Coalition Against the Misuse of Pesticides (NCAMP), chemical wood preservatives account for the single largest pesticide use in the United States and perhaps the greatest pesticide threat to public health and environment with the conventional wood pole leaving a trail of poisoning and contamination from cradle to grave, beginning with the forestry practices used to grow the trees, to the production of the chemicals, to the wood treating facility, to the installation, use, storage and disposal of the treated wood.
In February 2002, the U.S. Environmental Protection Agency indicated that they had reached an agreement with representatives of the wood-preservative industry to begin phasing out the residential use of Copper Chromium Arsenate (CCA). It is estimated that this will affect about 5% of the overall toxic wood preservative market. CCA only accounts for approximately 10% of the overall market, while utility poles alone account for nearly 12% of all wood preservatives used in the United States.
In addition to comprising toxic threats, wood utility poles also represent safety threats because utility poles and signposts create serious roadside hazards for automobiles. In 1996 alone, 11,859 people died in roadside hazard crashes. Of those deaths, utility poles accounted for 9%, collisions with guardrails accounted for 9%, and collisions with signs and signposts accounted for 7% of the deaths.
Hence, in view of the fact that waste tires represent an enormous solid waste burden upon states and municipalities, that utility poles represent major sources of health and safety threats, and that reducing the use of wood and wood products, including over 100 million utility poles that are permeated with wood preservatives, would be environmentally beneficial, the manufacture of cost effective construction materials from recycled waste tires, for example, shock-absorbing poles, guardrails, and barriers, could solve enormous solid waste disposal problems while simultaneously addressing environmental and public health and safety concerns.
In addition to the Applicant, others have appreciated the need to utilize waste tires for increasing environmental health. U.S. Pat. No. 5,246,754 (Miller) discloses a construction pole formed from discarded waste tires. Miller's construction poles are formed by 1.) cutting waste tires such that they may be flattened, and 2.) by rolling and gluing the flattened tires upon one another to eventually form a pole. While Miller's methods ultimately form a pole made from waste tires, his methods of cutting the tires in order to flatten them out causes waste and does not incorporate the whole discarded tire into the pole. Additionally, substantial amounts of potentially environmentally toxic glues must be used to secure the tires to one another. Finally, the utility pole disclosed by Miller does not comprise any additional means, other than glue, for providing stability to the structure.
Accordingly, there is a long felt need for utility poles and other construction materials constructed from discarded tires that utilizes the whole tire in its construction, does not use toxic preservatives and potentially toxic glues as a component of its construction, and which is structurally stable yet flexible in applications where desired, and aesthetically appealing.